Sorry Arnold, how do you work out the harmonic percentages in terms of how far below the signal is from the fundamental? I noticed 0.1 would be -60 below the fundamental and 0.03 would be -70. Please explain how that works. Thanks!

"Designers at ESS and other DAC manufacturers consult with these audiophiles to ascertain which dacs required work amongst their Sigma Delta designs to make it a class leader today.They literally had to invent new methods of diagnostics looking outside the traditional tools of audio analysis. They have moved way past measurements of frequencu response, distortion and signal to noise!Longish video and somewhat technical but your jaw will drop as all our differences, disputes and concerns have and are being addressed compehensively in an ongoing fashion. The short version: some people can hear differences that others can't and the designers have come to accept it and working with the "golden ears" now on their staff or actively consulting they are engineering improvements to their dacs that are superior to previous ones."

But mzil, just take your time to watch it. It might be delusional crap, but just tell me what you think. When you have time. That DAC designer is now asking me to provide evidence that distortion 100 dB down is inaudible, to contradict his findings.

But mzil, just take your time to watch it. It might be delusional crap, but just tell me what you think. When you have time. That DAC designer is now asking me to provide evidence that distortion 100 dB down is inaudible, to contradict his findings.

Worrying about things that are 100 dB down is like thinking your car will have discernibly better acceleration if you shake the dirt out of the floor mats to reduce the overall mass.

edit to add: Here's an on line demo which sort of shows you how quiet -100 dB is compared to normal levels, at least in a rough way. Be careful not to click on the top part of the chart untl you get a feel for how it works. [I take no responsibility for damage to hearing or equipment. Read the warnings there too.]

I watched all of it, sometimes pausing to read the slides, and I found it very interesting. Not because he claims that a small minority of people in some extremely rare corner cases is able to hear surprisingly small differences, but because of all the other interesting stuff he explains along the way.

Apart from the obvious goal to make people choose ESS's products over the competitor's, as far as I'm concerned there's no snake oil in the presentation. I would recommend it to anyone with a general interest in audio technology, perception or chaos theory.

Worrying about things that are 100 dB down is like thinking your car will have discernibly better acceleration if you shake the dirt out of the floor mats to reduce the overall mass.

edit to add: Here's an on line demo which sort of shows you how quiet -100 dB is compared to normal levels, at least in a rough way. Be careful not to click on the top part of the chart untl you get a feel for how it works. [I take no responsibility for damage to hearing or equipment. Read the warnings there too.]

I watched all of it, sometimes pausing to read the slides, and I found it very interesting. Not because he claims that a small minority of people in some extremely rare corner cases is able to hear surprisingly small differences, but because of all the other interesting stuff he explains along the way.

Apart from the obvious goal to make people choose ESS's products over the competitor's, as far as I'm concerned there's no snake oil in the presentation. I would recommend it to anyone with a general interest in audio technology, perception or chaos theory.

A lot of it is messed up. Explained earlier in the thread mentioned below. I would hope that nobody who lacks a good BS manager spends any time with it.

It is very true. For example most audio professionals who depend on listening, as they get older they acquire one or more younger engineers that they train how to listen, and then rely on their ears.

Others get really good at interpreting measurements.

I know people with well known names who can't hear stuff that is very clear to me, and I'm 66 and have had one bad ear since I was 8. I have done well in ABX tests regardless.

QUOTE

They are called "delusional". [I didn't watch the video since they are either kooks or crooks. Either way, a waste of my time, and yours.]

Depends if the hearing of things that others cannot passes some kind of sniff test, of which ABX is a very good one.

I never call it delusional though, I call it Illusional which is a very carefully chosen word.

It is true that delusions may set the stage for the credibility that they give their illusional experiences.

I still remember Dr Larry Greenhill (Stereophile and Audio Magazine reviewer) whose day job was being a shrink at a state mental facility comment on which well known names in audio he believed were uimmm (my word) nuts.

It is very true. For example most audio professionals who depend on listening, as they get older they acquire one or more younger engineers that they train how to listen, and then rely on their ears.

Sure, but then one can't really dismiss the claim that they can hear distortion products 100 dB below the fundamental, right? I mean the claim sounds bonkers, but if people can perceive things that others can't, then ...

Unless there any studies of human audibility thresholds that are statistically relevant that show humans can't perceive distortion below a certain point?

You may be mischaracterizing whet Arnold said. It's true that hearing varies, and that training and experience have a significant impact on the ability to hear more subtle aspects of sound, but decades of research have pretty accurately set a lower limit on what is possible in human hearing. We also have a pretty good understanding of the mechanism of hearing, and this is also consistent with what we have found in practice.

Sure, but then one can't really dismiss the claim that they can hear distortion products 100 dB below the fundamental, right?

But you can turn the burden of evidence around - if they can hear distortion products 100 dB below the fundamental, it should be easy for them to prove it under controlled lab conditions. Have they? If not, why not?

I was having a debate with a DAC designer who cited these graphs as reasons for his sonic preferences, especially the first graph. He claimed that the harmonic distortion was the reason why he preferred the sound. But you are saying that the harmonic components are so far down, 100 dB's down and therefore inaudible.

Here are the impulse response graphs, respectively :

In the beginning of this thread i suggested you may look at the frequencies this happens. Did you ask the "DAC designer" you are debating with meanwhile for graphs showing this or even the frequency response of these filters? Did you try on your own?

Worrying about things that are 100 dB down is like thinking your car will have discernibly better acceleration if you shake the dirt out of the floor mats to reduce the overall mass.

edit to add: Here's an on line demo which sort of shows you how quiet -100 dB is compared to normal levels, at least in a rough way. Be careful not to click on the top part of the chart untl you get a feel for how it works. [I take no responsibility for damage to hearing or equipment. Read the warnings there too.]

Sorry slightly off topic, but could you use the results from that Hearing Test to help determine the best setup for a parametric EQ?

It is a crude test just meant for fun. In real audiometry they use a single blind protocol (you don't test yourself and see a score card showing your level selection from of the previous trial frequency, which may bias your next selection) and calibrated headphones playing at a pre-established, measured level [Not "Here, to start, set this knob to, er, comfortable level, whatever that means to you"] .

Unless there any studies of human audibility thresholds that are statistically relevant that show humans can't perceive distortion below a certain point?

There are shelves full of journals full of masking data probing what kind of signal makes what other kind of signal inaudible, for different listeners, at whatever level. The data has been collected for a century. Google auditory masking. Try Google Scholar to see the depth of the research (it's well mapped for many animals on this planet, not just humans!).

It is a crude test just meant for fun. In real audiometry they use a single blind protocol (you don't test yourself and see a score card showing your level selection from of the previous trial frequency, which may bias your next selection) and calibrated headphones playing at a pre-established, measured level [Not "Here, to start, set this knob to, er, comfortable level, whatever that means to you"] .

It is very true. For example most audio professionals who depend on listening, as they get older they acquire one or more younger engineers that they train how to listen, and then rely on their ears.

Sure, but then one can't really dismiss the claim that they can hear distortion products 100 dB below the fundamental, right?

Which they?

You are missing the point. The 100 dB number is better than what the best young listeners can achieve.

QUOTE

I mean the claim sounds bonkers, but if people can perceive things that others can't, then ...

A key part of listener selection and training is monitoring people's sensitivity as compared to other listeners. One of the tests we applied was to look at the individual scores and see if any of the listeners did consistently better. Some people who did consistently poorly were taken aside and encouraged to not participate in the group tests. Some tests were by invitiation and we were careful who we invited, and I mean this in a good way.

When a few people did exceptionally well, we did additional trials with them to see if their results were real or a statistical anomaly. You know if you flip coins, you may get long runs of heads or tails. If you do enough flips, additional flips even things out. Same thing can happen with listeners.

We also had situations where people would do worse than guessing. We watched the tests carefully and noticed that this could happen when the listeners were unconsciously communicating, such as groaning when they were having a tough time hearing differences. One of the things about ABX is that if you are having problems hearing a difference, you generally know it long before you score the test.

Later on I did quite a bit of work with tests involving a known difference that was varied in size. I would start listeners out with large differences, and make the difference smaller in subsequent tests. Eventually, the listeners with working with the natural difference. This made it possible to see who was capable and who was trying versus those who were not trying all that hard or were simply not getting it.

QUOTE

Unless there any studies of human audibility thresholds that are statistically relevant that show humans can't perceive distortion below a certain point?

There are usually a number of different ways to estimate the audibility of a given kind of artifact. You can do different kinds of tests involving the same artifact. Sometimes you can estimate the audibility of an artifact from things like the Fletcher Munson curves or masking curves. In those cases where the same artifact is tested for a number of independent ways, they often give very consistent results.

For example you can estimate the audibility of an artifact using both ABX and ABC/hr tests, which are actually very dissimilar listening tests. The key is that no matter how you present the alternatives or how you ask people to compare them, when they are hearing something their responses correlate with the presence or absence of the stimulus, and when they are not hearing something their responses become random.

There are also other kinds of testing besides presenting samples. You can give people an unmarked knob that varies the level of the artifact, and let them turn it up and down until they feel that they have homed in on the level where it is just audible. This same scheme is used in audiometry - ear tests. It is arguably not exactly double blind, and a creative listener can spoof it, but it can also give very good results.

When people say that a lot of this stuff has been tested to death, they are not kidding!